1. Technical Field
This invention relates generally to rotary drill rigs and, in particular, to devices for assisting an operator of a rotary drill rig to identify progress of a given drilling operation.
2. Description of the Related Art
Drilling operations in a coal mining environment are quite harsh. Known rotary drills typically include an enclosed steel and glass operator's cab to protect a rig operator from the weather, noise and other elements. During such drilling operations, however, the rig operator must be quite careful to ensure against overdrilling into the coal seam, which significantly reduces yield and increases cost. The operator is not always able to determine when the drill has reached the coal seam due to the relatively closed cab environment.
The present invention addresses this problem.